IB Biology HL IA - „How is the activity rate of the juice production affected when an enzyme is used in different concentrations (0,0 ml, 0,5 ml, 0,75 ml, 1,0 ml, 1,25 ml, 1,5 ml), while the mass of the fruit (pear; 30g) is not being changed?”
Background/hypothesis:
Enzyme is a substance that is created by a living organism that acts as a catalyst to bring about a biochemical reaction. Enzyme can be affected by its own environmental conditions. These conditions may include temperature, pH level, or the concentration of the enzyme or the substrate (enzymes catalyze a reaction which involve a substrate, however after the reaction, the enzyme is unaltered while the substrate is a part of the end product). Cellulase is an enzyme (aka biological catalyst). Cellulase is a substance that can be found within the cell wall of fruit which keeps the cell firm. Pear has a thick and though cell wall which cannot be broken very easily, therefore taking a while until the juice is extracted naturally. In order to extract juice from a fruit, the cell wall (cellulose) has to be broken. Cellulase increases the speed of the cell breakdown therefore increasing the speed of juice production. The more cellulase is added to a pear (pyrus communis), the more juice will be produced over a specific period of time. Different amount of cellulose is used on the same amount of pear, to show how cellulace affects the speed of cell breakdown, therefore the extraction of juice. In this experiment, five different concentrations of cellulace (independent variables) will be used (0,0 ml, 0,5 ml, 0,75 ml, 1,0 ml, 1,25 ml, 1,5 ml) to show its efficiency.